1. Field of the Invention
The present invention relates to a motor brush dust removing filter for use in a vacuum cleaner, and more particularly, to a motor brush dust filter for a vacuum cleaner in which brush dust from a brush assembly of an electric motor employed to generate suction power of the vacuum cleaner is prevented from being discharged.
2. Description of the Conventional Art
A typical vacuum cleaner, as shown in FIG. 1, includes a cylindrical canister 10, a supporting member 11 having wheels 11a at a lower portion of cylindrical canister 10, an air outlet 12a for discharging air at an upper portion of cylindrical canister 10, and a vacuum generating unit 13 for sucking air into cylindrical canister 10.
Vacuum generating unit 13 is made up of a vacuum chamber 13a, a filter 13b, an air suction fan 13c arranged on suction filter 13b, and a motor 14 for driving air suction fan 13c. 
When an electric motor 14 is driven by power supplied thereto by a user, air suction fan 13c rotates so as to generate in a space of suction filter 13b, i.e., vacuum chamber 13a, a vacuum state. Then, debris is sucked in via a hose 13d by the suction force of vacuum chamber 13a. 
Thus, sucked-in substances are filtered by filter 13b, and the air passed through filter 13b is discharged outside via air outlet 12a. 
Electric motor 14 employed for a rotation of air suction fan 13c is a common electric motor which uses a brush assembly 14a to provide a rotator with power. It is a common practice to place brush assembly 14a onto electric motor 14, wherein brush assembly 14a has at top surface thereof an air vent 14b so that a heat generated from the friction of the brush may be cooled down and a brush dust may be discharged.
To prevent the brush dust generated by the operation of brush assembly 14a of motor 14 from being discharged out via air outlet 12a, a conventional solution places a cover 15 having a non-woven fabric or a sponge 15a attached thereto over air vent 14b, so that the brush dust can be roughly collected and caught by a non-woven fabric or a sponge 2c which is attached inside air outlet 12a. 
However, such a conventional brush dust collecting unit has disadvantages in that brush dust may not be completely blocked since cover 15 cannot be placed closely to air vent 14b considering cooling of inner heat generated by the operation of electric motor 4.
Therefore, it is an object of the present invention to provide a motor brush dust removing filter for use in a vacuum cleaner in which the brush dust from a brush assembly of an electric motor may be discharged via an additional outlet and a filter is embedded in or attached to the outlet, to thereby allow an efficient cooling of the brush assembly and a complete blocking of the brush dust.
To accomplish the above object of the present invention, there is provided a motor brush dust removing filter for use in a vacuum cleaner, the vacuum cleaner including a cylindrical canister, a support member having wheels installed under the canister, an air outlet in a cover for discharging air from an upper portion of the canister, and a vacuum generating unit containing an electric motor for sucking air into the canister, wherein the cover has at a center thereof a circular aperture, a circular protrusion along the aperture, a filtering member, and a brush dust removing filter having a connection portion attached to a case of the motor brush assembly, so that brush dust discharged via an air vent formed at an upper surface of the brush assembly case is filtered by the filter of the filter unit and directly exhausted to the atmosphere.